


Pulse

by Linderosse



Category: Fire Emblem: Fuukasetsugetsu | Fire Emblem: Three Houses
Genre: But... damn; it must be terrible to live with those memories, Divine Pulse is a great game mechanic, F/F, Hurt No Comfort, Hurt/Comfort, M/M, The Black Eagles are wonderful and I love them
Language: English
Status: Completed
Published: 2020-12-25
Updated: 2020-12-25
Packaged: 2021-03-10 19:35:59
Rating: Teen And Up Audiences
Warnings: Graphic Depictions Of Violence, Major Character Death
Chapters: 1
Words: 3,602
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/28312461
Author URL: https://archiveofourown.org/users/Linderosse/pseuds/Linderosse
Summary: They die, live, and die again. Byleth walks the line between honoring their memories and trying to keep herself sane.
Relationships: Caspar von Bergliez/Linhardt von Hevring, Dorothea Arnault/Petra Macneary, Edelgard von Hresvelg/My Unit | Byleth, Ferdinand von Aegir/Hubert von Vestra
Comments: 5
Kudos: 67





	Pulse

In the past, Byleth had never let her students die. The flow of battle back then had been an orderly dance with minor spikes of chaos: in essence, nothing too difficult to navigate. Byleth’s own prowess, the assistance of the Knights of Seiros, and Sothis’ guidance together had all been more than enough to ensure everyone’s safety.

Well, sure, she’d had to rewind sometimes. Sothis had always laughed at her for that— for using Divine Pulse when it was technically still possible, although not probable, for them to win. But no one had died, even in the alternate futures she had ripped away. Byleth made sure of it.

Now, things are different.

This is war, and Byleth has learned that war is above all else _unpredictable_. She cannot be everywhere at once, and neither can Linhardt, who has learned to ride a horse just so he can reach the wounded in time to save their lives.

As the war progresses, they _all_ work hard to keep each other alive. Hubert makes plans and counterplans for every situation. Ferdinand rushes the front lines and takes the brunt of physical damage. Bernadetta snipes potential threats from a distance, and Petra and Caspar eliminate foes before they can retaliate. Dorothea’s songs give everyone hope— even standing next to her is like a restorative balm in battle.

Emperor Edelgard is a tower of strength, and her allies take refuge behind her as she carves a path through their foes.

Still, it is not enough.

* * *

The first death is Bernadetta. Byleth could have sworn the girl would survive that blast—

Bernadetta’s breathing comes in sharp, short gasps. She writhes silently in the dirt, burns covering her entire right side. Her horse is already on the ground, unmoving.

Byleth rushes to her, throws herself to her knees by the young archer’s side.

She wants to say something. Anything. Words of comfort, something to help the girl, assurances that Dorothea is on her way— 

Nothing comes to mind. And Byleth finds herself still kneeling, wordless, as Bernadetta’s shudders slowly come to a halt. Her limbs fall to the ground, unsupported, and all Byleth can do is watch, frozen, until there’s nothing left of the shy, scared girl who wouldn’t leave her room until her classmates gave her a reason to believe in herself.

The others have noticed. Caspar is nearby, and Byleth notices somewhere in the back of her mind that he’s shouting. Feet are rushing over. Shocked hands clasp over open mouths, wide eyes stare unblinkingly at the corpse of their classmate— their comrade in arms— their friend.

Byleth can’t let this go on a moment longer.

_“Divine Pulse!”_

The world shatters into glimmering violet shards and rushes past her as Byleth spins the wheel of time backwards. Bernadetta shudders and revives before Byleth’s panicked eyes. Flesh knits itself together, cloth mends, and the girl is back on her horse, her bow in hand and an arrow nocked and ready, aiming at a mage who will retaliate with a Bolganone spell that will prove just a bit too powerful.

The spinning stops. Byleth’s headache fades.

And this time, Byleth screams a warning before Bernadetta can fire that arrow.

“ _Wait!”_

Bernadetta pauses, turns to her teacher.

“Professor? H-Have I done something wrong?”

Byleth shakes her head. She hopes it isn’t obvious that her breath is stuttering, that her gaze fidgets as she forcefully quashes her panic.

“Not at all, Bernadetta. Just… leave the mage for now. Go help Caspar and Ferdinand take down that pegasus knight.”

Determination gleams in wide purple eyes. “Got it, Professor!”

Byleth lets herself breathe.

* * *

Byleth wakes up gasping for breath, the next few nights. Visions of Bernadetta’s charred corpse plague her dreams.

She forces herself to sit up in bed and take a look around. Her room at Garreg Mach is quiet, almost peaceful. It’s fine. Nothing happened. Bernadetta is alive, probably sleeping now, just a few doors down from where Byleth currently is. None of the children are gone— and she still thinks of them as children, even though she’s no longer their professor, even though some of them may very well be older than her.

Not for the first time, Byleth wishes Sothis were still here to share her burdens. But the lively goddess with the youthful grin exists only in Byleth’s soul, now.

Where else could Byleth go for comfort? Certainly not to the one person she truly wants to run to— for in no possible way could Byleth ever tell Edelgard what she has seen. The Empress has enough burdens of her own.

* * *

Petra falls next.

A small skirmish— just an unimportant mission to take down some bandits, and Byleth miscalculates.

“Petra, head north. Stay under cover in the foliage, and when the enemy attacks and misses you, retaliate.”

Petra gives the northward pass a glance.

“Professor? It is looking as if there are many soldiers in the path. I am having thoughts that— I _think_ that they might hit me, even if I am being in the cover.”

Byleth claps her on the shoulder, already calculating where she’ll send Edelgard next. “You’ll be fine, Petra. Go.”

And the swordswoman just nods and complies. Why hadn’t she further questioned Byleth’s orders? Why hadn’t Byleth _listened?_

Byleth doesn’t see the axe cut through Petra’s legs. But she does hear Dorothea’s scream.

She runs.

Byleth grinds to a halt in front of two girls, half hidden in the sparse bushes. They are drenched in blood, far too much blood. Dorothea kneels over the prone form of the princess of Brigid, the huntress’ head pillowed on singed and bloody grass. She— Petra— her eyes are closed, dark lashes shuttered, her lithe form abnormally still as the battle rages on in the distance. There’s a small, faint, smile on the swordswoman’s face. The accompanying despair flickering across Dorothea’s pale visage as she glances up desperately at Byleth is enough to tear a crack across Byleth’s heart. 

And Dorothea is _singing_. The song is ethereal, soft, like a lullaby, yet not quite like anything Byleth has heard before. It’s something from the opera given a forlorn new meaning, twisted by sorrow into a scale it wasn’t meant to be sung in, notes wrenched out of shape into a staggering cascade of emotion.

The two forms, kneeling in the grass, one crying over the other— It is just like what happened with Bernadetta, all over again, just like what happened with Byleth’s father, with Jeralt Eisner—

Byleth can’t bear to see this any longer. But this time, she cannot simply rewind. Not yet. She wasn’t there when Petra was killed, and— and she has to know exactly how, so that she doesn’t repeat the same mistake again.

As Byleth approaches, though, Dorothea stops singing. The leaves around them rustle as Dorothea gently, ever so gently lifts Petra’s still form into her lap. She brushes a strand of Petra’s hair from her face, and if her fingers trail across skin for just a bit too long, Byleth cannot fault her for it.

And this— this is the worst part. The worst part is when Dorothea stands and wipes the tears from her eyes, and she takes a deep breath, and her expression goes _blank_ and _hardens_ , a porcelain mask on a practiced performer. She looks Byleth right in the eyes.

“Petra’s dead, Professor. Was there something you needed me for?”

Byleth doesn’t want to have to ask her to relive this. It helps to know that Dorothea won’t remember this incident at all, that this will all be erased from the strands of time soon enough.

Byleth refuses to prolong this by being subtle. She gets to the point. 

“How did Petra die? Who killed her?”

Dorothea must assume that Byleth wants revenge, because she answers without pause nor confusion, not a crack showing in that horrible blank expression.

“Two brigands from the north. Reinforcements came in for the enemy, Professor. If I had gone into the northern pass along with her, if I had known the brigands would be there, I might have—“

She stops as her mask threatens to falter. Byleth should just rewind, right now. Yet Dorothea’s blank face… Byleth feels the illogical need to comfort her. She places a comforting hand on Dorothea’s shoulder.

“Dorothea, please. Allow yourself to mourn. Can you do that for me?”

Dorothea stands up at Byleth’s prompting and carefully leans into Byleth’s side. She doesn’t stop looking at Petra’s still form on the ground, and she stays silent. But tears begin to stream down her face, and she’s biting her lip, her face shadowed in despair.

“It’s alright, Dorothea. It’ll be alright, I promise.” Those words must sound so empty to the young songstress. Byleth, however, means them from the depths of her heart. She wouldn’t lie to one of her beloved students. Not about something like this.

“ _Divine Pulse.”_

This time, Byleth sends Dorothea and Petra into the northern pass together.

* * *

Petra’s corpse joins Bernadetta’s in Byleth’s dreams, and when Byleth wakes, gasping in the night, she knows she has to do something to keep herself sane.

She pulls out a quill pen and begins to write.

_Dear Sothis,_

_I cannot thank you enough for your gift to me, the Divine Pulse that erases my failures from all minds but my own. Yet in a way, it is a curse, for I have no one with whom to share this sorrow. No one, other than the part of me that is now you._

_And so, to keep the memory of those failures from festering within me, I hereby commit them to parchment. As I write, I hope you are reading this._

_On the 13th day of Horsebow Moon, I…_

* * *

For just a few seconds, Ferdinand is still alive. The oh-so-familiar woman whose axe is embedded in his chest leaps backwards, pulling the axe out, a flash of sorrow and resignation displayed ever so briefly on her face. Her long pink hair whips around her shoulders as she retreats further into the city of Deirdriu.

Hubert surges forward with a shout to catch Ferdinand’s body as it falls.

Byleth sees the pink-haired figure in the distance pause, briefly, and maybe even look back, but Hubert doesn’t notice. The dark mage’s gaze is locked on the fading life in his arms.

Hubert grits his teeth, shifts Ferdinand to one arm, and lets his hand hover above Ferdinand’s broken chest. 

“Heal.”

He’s not amazingly skilled at faith magic. Either way, Byleth doesn’t think it would make a difference— the axe wound from Freikugel has carved away a large chunk of Ferdinand’s chest, to the point where even Linhardt wouldn’t be able to do anything about it. As it stands, Hubert’s healing spell repairs a few patches of skin and bone, then fizzles away into pale violet sparks.

Ferdinand seems consumed by shock. He’s gasping for air, eyes wide. He tries to glance down at his chest, but Hubert holds him back with a firm hand on his forehead.

“Don’t look, von Aegir.” Hubert’s voice has a strange note to it.

Byleth struggles to _think._ She can’t rewind yet, because she _doesn’t have a plan._ How can she defeat the Leicester Alliance’s second in command without Ferdinand dying again? Because her first plan, to lure the axewoman out with Ferdinand’s high defense as a safeguard— that had gone just _perfectly,_ hadn’t it? Yet, if they don’t do that, Hilda’s forces will catch up to them before Hubert can get out of the way, and, and—

Byleth knows Ferdinand has seconds left to live.

Ferdinand looks up at the dark mage holding him. His breaths come faster now, stuttering, and he starts to choke.

“Hubert? —Can’t— breathe…”

“Shh. I know, von Aegir. Be silent.”

“You— I need to—”

“It’s alright. Rest now, Ferdinand.”

“No! I—”

Ferdinand doesn’t get the chance to complete the sentence before he chokes on his own blood and starts to spasm. Hubert continues to hold Ferdinand, leaning closer to whisper something that Byleth can’t hear.

Byleth wracks her brain to come up with a strategy. She needs a plan so she can rewind, so she can erase this fate. Maybe, if she could send Bernadetta to take out the pegasus knight— but no, the archer is too far away— 

Time runs out while Byleth is still thinking. Within moments, the light fades from Ferdinand’s eyes.

Byleth doesn’t think she’s ever seen Hubert cry. 

Yet here he is on the unforgiving stone tiles of the Aquatic capital, tears dripping down his sallow face, completely silent. A gloved, bloody hand rises slowly to hover over his mouth as his other arm cradles Ferdinand’s body. The cavalier’s head lies tilted precariously against Hubert’s shoulder, eyes still open as his blood drips to pool at Hubert’s feet. Half of Ferdinand’s chest is missing. Judging by the dark mage’s expression, the same can be said of Hubert.

Hubert clutches the corpse in his arms and a change comes over his expression.

“Hilda. Valentine. _Goneril._ ” Hubert spits out, standing. Each word is a curse meant to wreck a thousand worlds. Black miasma materializes over his open palms.

“She will _pay_ for this—”

An idea for a plan finally forms in Byleth’s mind. She doesn’t waste a second more.

“ _Divine Pulse!_ ”

The wheel of time deposits Byleth in the past, and Byleth jumps into motion, yelling for Linhardt’s battalion to cast Stride on Bernadetta’s mount. The archer arrives in time to shoot their former schoolmate, wounding the axewoman so that Ferdinand can deal the final blow. This is a different sorrow, but one that Byleth has resigned herself to. Nothing’s fair in love and war. Byleth briefly registers that Claude screams something, but there’s no time to deal with that, not when others of her students might be in danger.

Hubert may not be fully aware of it, but his gaze follows Ferdinand without pause as the cavalier delicately balances celebrating a victory and mourning an ally-turned-enemy.

“Professor,” Hubert addresses Byleth, though his eyes are still on Ferdinand. “I’m not sure why, but… for just a second, right before Ferdinand attacked, I was consumed by an overwhelming anger towards our fallen foe over there. I suspect a curse of some sort— though I can’t imagine what our enemy would gain by provoking anger in me against Miss Goneril. Perhaps it was a misfire. Or perhaps they meant the anger to drop our vigilance. In any case, keep an eye out for similar symptoms in the others, Professor. This could endanger our cause.”

Byleth… knows exactly why Hubert felt that inconsolable rage, but… 

This shouldn’t be happening. A jolt runs through her as she realizes the consequences of that one simple admission by Hubert— that it’s possible for thoughts to leak through from an erased branch of the timeline.

She can’t let herself focus on this now— she has to plan a war. She pulls her mind away from this and finds the flow of the battle once again.

* * *

The next few skirmishes progress without a hitch. Byleth doesn’t even use Divine Pulse once. Of course, nothing seems different to the others of the Black Eagle Strike Force— they’ve gotten used to excellence from their Professor. If only they knew how many times Byleth usually has to try in order to get things right.

The battle after that is a nightmare.

* * *

It begins well, as battles tend to. Byleth had left Caspar and Petra at a crossroads and forged ahead to the west with Edelgard and the others. Arianrhod is known as an impregnable fortress for a reason. It wouldn’t do to underestimate the Kingdom’s defenses.

Yet it seems that is what she has done. Petra swoops down, shouting as she descends for Linhardt to follow her. Linhardt pales. Byleth feels her blood run cold.

By the time they arrive it’s too late. It’s _clearly_ too late. There’s an arrow embedded in Caspar’s eye— no mortal can recover from that.

“Caspar?” Linhardt asks. His voice is less of a voice and more of a light, tremulous breeze.

He dismounts and kneels at Caspar’s side to whispers, “Recover.”

A burst of green-tinged light arcs from his hands. The Crest of Cethleann manifests in the air in front of Linhardt, above the fallen brawler. Still, nothing happens. Linhardt takes in a deep, shuddering breath.

“Recover,” he mutters again. And then again, and again, and the faith mage’s green robes are now brown with blood and his hands are directly on his partner’s chest as if he can simply shove the magic into him; force the broken body beneath him to accept that it should live.

Byleth grabs Petra, pulling her aside. “When did this happen?”

“It is happening not too long ago, Professor.” Petra’s eyes are filled with sorrow but she doesn’t look at the corpse, instead preferring to scan her surroundings, ever vigilant. Her stance shifts slightly to optimize dodge time. Byleth looks down, and suddenly all she can see is those same lithe legs hewn off at the thighs, blood pouring from them onto thick forest grass. Byleth shakes her head to clear it.

The green glow around Linhardt’s hands fizzles out. He stares at the blood left behind with a strange, empty gaze. His breath quickens with subdued panic as slow shivers wrack his frame.

“It shouldn’t be so easy for a life to fade,” he says quietly, and his voice is almost normal except for the harsh shuddering breaths between his words. He tears his gaze away from the blood on his hands with force, only for his vision to be ensnared again by the sight of the corpse in front of him. 

“What’s the point of it all, then?” Linhardt’s voice is a mere whisper now. “My crest—? My research—? What am I supposed to _do_ now, Caspar?”

“ _When_ , Petra? I need a more exact time.” Byleth says again, insistently. On impulse, she grabs the woman’s shoulders and shakes them, just once. “As precise as you can get it.”

Petra looks into Byleth’s eyes and seems to notice something there— madness, perhaps. Byleth does feel a little mad. She wouldn’t blame the huntress for having doubts.

But this is Petra, and Petra trusts her. 

Petra is also observant to a fault. “Four minutes ago— no, three and a half minutes. It is being hard for me to recall with more exactness than that.” 

Byleth nods. Great. She can rewind with Divine Pulse up to any time after the start of the battle. It’s like a running checkpoint, for her. It’s useless unless she sets it manually, which requires her to know that something might go wrong. She sets the checkpoint at the start of every battle just in case situations like these occur— 

In a flash, Petra’s eyes widen and she shouts something in a foreign language, looking over Byleth’s shoulder. Byleth spins to look but isn’t able to complete the motion as she is abruptly shoved over. It takes her seconds to realize that Petra is the one who shoved her. In those vital seconds, a flier swoops over the fortifications and hurls a javelin over Byleth’s prone form and into Petra’s chest. Petra grits her teeth and, still impaled through, raises her sword at the familiar blonde woman who threw the javelin. The blonde woman draws a new lance and they clash.

But Byleth is no longer able to watch this battle, because a swordsman has leapt through the doorway and is dashing at Linhardt.

Byleth struggles to her feet. Time speeds on, but it feels like Byleth is moving through molasses as she throws herself at Linhardt with all her might. She hears Petra shout something else in the language of Brigid except the statement is cut off abruptly before it is finished and Byleth doesn’t want to look behind her because every drop of energy she has is focused on intercepting the swordsman with the dark hair and red eyes and bright glowing shield that casts a harsh light upon his sharp face that’s lined with the intent to kill, and—

Byleth isn’t even close. She grinds to a halt as the swordsman sends his blade neatly through Linhardt’s back, just to the side of his spine and through his ribcage. Linhardt looks down at the blade and seems to _accept_ it. He lets his arms drop to his sides, takes Caspar’s hand, and closes his eyes. And right there, kneeling on the ground like he’s about to take one of his impromptu naps, Linhardt von Hevring dies.

Byleth screams.

The world shudders around her and shards of purple glass appear and break and shatter and Byleth can barely even see it happen. In the time she spends going back, she heaves deep, gulping breaths. She dashes away the tears from her eyes. She schools her face back into the strict composure she’d found it so easy to maintain in the past.

When she arrives, all the way back at the entrance to Arianrhod, she is Tactician Byleth of the Black Eagles Strike Force again.

“Are you alright, my teacher?” Edelgard asks her, quirking an eyebrow.

“Yes. I'm fine.”

“Nervous, Professor?” Hubert quips.

“Not at all.”

Lies, of course, but they’re becoming more true as Byleth watches Caspar grin and intertwine his fingers with Linhardt’s while the subdued mage smiles tiredly back.

* * *

_Dear Sothis,_

_Three at once, this time. Am I becoming lax in my vigilance? Perhaps so, for I begin to see their ghosts in the halls, as if they weren’t still alive and healthy as I write…_

**Author's Note:**

> Thus do I return to this fandom. Kudos and comments are very much appreciated, as always!
> 
> Edit: Here’s my headcanon for how Divine Pulse works. I’m sure I’m not the only one who sees DP this way, but I thought I’d share just in case! It explains why Byleth is able to rewind at any time during a battle, yet is unable to save people who die in the storyline. 
> 
> As I mentioned in the fic, I envision DP as a checkpoint that takes a considerable amount of energy to keep running. During any time when the checkpoint is running, Byleth can rewind to any earlier time in that checkpoint’s history. However, once the checkpoint is dispelled, that saved history is lost, and Byleth can no longer rewind to any of those times.
> 
> So how does that work? Byleth knows something might go wrong during a battle, so she starts the checkpoint before the battle begins. She keeps it running until the battle is over, then dispels it. In Jeralt’s case, she had already dispelled the checkpoint from the previous battle. She quickly set a new one once she realized what Monica was up to. From that point, she could only rewind as far back as the instant she realized the threat. Sothis tells her to stop once they both realize they can’t rewind far back enough to make a difference. In Rodrigue’s case, Byleth never actually realized anything was wrong until it was already over. No chance to rewind at all.
> 
> And that’s it!
> 
> In unrelated news, will I continue the [Colors of Fódlan](https://archiveofourown.org/series/1536050) series soon? I'm not sure. Perhaps when I replay Crimson Flower. I do still love this game quite a bit.


End file.
